Spring bolt night latch

ABSTRACT

A spring bolt night latch assembly secured to the door of an enclosure and cooperating with a suitable strike mounted on the door frame and including a spring-biased reciprocable latch bolt in a latch housing and a rotatable knob cooperating with the bolt to retract the bolt from its biased latched position. The knob has a pair of spaced actuating projections, each of which cooperates with a retracting camming surface on one side or the other of the bolt; one retracting surface providing retraction where the bolt will be projected under spring force upon release of the knob, and the other retracting surface cooperating with its knob projection to retain the bolt in fully retracted position. A pivotally mounted pawl cooperates with the latch bolt in projected position to dead lock the bolt.

United States Patent Orr Oct. 23, 1973 [5 SPRING BOLT NIGHT LATCH 755,359 8/1956 Great Britain 292 337 [75] Inventor: John L. Orr, Rockford, Ill.

Primary Examiner-Albert G. Craig, Jr. [73] Assrgnee. fiecystgzizrgonlslohdated Industries Att0mey A. w Molina": at a.

[22] Filed: Dec; 20, 1971 [21] Appl. No.: 209,568 [57] ABSTRACT A spring bolt night latch assembly secured to the door [52] U S. u 292/169 15 292/169 l7 292/337 of an enclosure and cooperating with a suitable strike 51 hit. Cl. IiIOSc 1/06 mmnted the frame and including [58] Field l 292/153 169 15 biased reciprocable latch bolt in a latch housing and :1 292/169 'g 38 rotatable knob cooperating with the bolt to retract the 7 bolt from its biased latched position. The knob has a [56] References Cited pair of spaced actuating projections, each of which cooperates with a retracting camming surface on one UNITED STATES PATENTS side or the other of the bolt; one retracting surface 601,077 7 3/1898 Jackson et al 70/l50 providing retraction where h bolt will be projected 337,115 3/1886 ;g under spring force upon release of the knob, and the I Ei ain i l I 15 other retracting surface cooperating with its knob pro- 466 373 1/1892 Roger s 70/l'50 jection to retain the bolt in fully retracted position. A 1 619 789 3 1927 Vogt...:::..................::::::E/169.21 Pivmally mmmted P COOPeFate-S with the latch FOREIGN PATENTS OR APPLICATIONS 630,385 lO/l949 Great Britain 29 2/169.l5

in projected position to dead lock the bolt.

10 Claims, 14 Drawing Figures SPRING BOLT NIGHT LATCH The present invention relates to a spring bolt night latch assembly and more particularly to a latch construction having a spring-biased latch bolt having a spring-biased latching position or a dead-locked projected position, or the latch bolt can be positively retained in a retracted position to prevent latching. In view of the present concern for security in homes or business to prevent unauthorized entry, security locks of the dead bolt variety are becoming more in use on entrance doors. Burglars or others attempting entry have found ways of circumventing many'of these locks by forcing the bolt or other means to gain entry. The present invention provides a night latch having a dead bolt arrangement where thebolt cannot be forced by jiggling, hammering or other measures exerted on the end of the bolt. 7

Among the objects of the present invention is the provision of a spring bolt night latch assembly having a unique arrangement and design requiring fewer parts and providing a simpler assembly. The latch includes a reciprocable spring-biased latch bolt and a rotatable knob mounted in a housing. The knob extends through the housing and has an inner exposed end adapted to receive the tail piece of a conventional rim cylinder lock mounted in the surface of the door opposite to that upon which the housing is mounted. Rotation of the knob through an arc of approximately 90 in either direction of rotation will retract the latch bolt against I the force of the spring.

Another object of the present invention is the provision of a spring bolt night latch assembly having a novel mode of operation. The knob has a pair of spaced camming projections which cooperate with a pair of camming surfaces formed on the rear end of the latch bolt. If the bolt operating knob is rotated in one direction, the bolt is drawn in against the force of the spring and, on release of the knob, the bolt and knob return to their initial positions. However, if the knob is rotated in the opposite direction, the bolt is drawn in and retained in its fully retracted position until the knob is manually turned in the opposite direction to release the bolt and allow it to spring out to its initial position.

A further object of the present invention is the provision of a spring bolt night latch assembly having a dead locked position when the bolt is projected to latched position. The dead locking arrangement includes a knob actuated pawl mounted in the housing and normally held in an inactive position by a detent arrangement. The pawl may by manually turned to a position engaging the latch bolt in its projected position to dead lock the bolt.

Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.

In the drawings:

FIG. 1 is a perspective view of the spring bolt night latch assembly.

' 7 FIG. 2 is a rear elevational view of the night latch with the base broken away and showing the latch components in their normal latch position.

FIG. 3 is a rear elevational view similar to FIG. 2 but showing the position of the latch bolt upon rotation of the knob in one direction.

FIG. 4 is a rear elevational view similar to FIG. 3, but showing the latch bolt retained in retracted position upon rotation of the knob in the opposite direction.

FIG. 5 is a rear elevational view of the base on a reduced scale for the latch housing.

FIG. 6 is a horizontal cross sectional view taken on the line 6-6 of FIG. 5.

FIG. 7 is a rear elevational view of the latch bolt.

FIG. 8 is a front elevational view of the latch bolt.

FIG. 9 is a side elevational view of the latch bolt.

FIG. 10 is a perspective view of the rotatable knob.

FIG. 11 is a rear elevational view of the knob.

FIG. 12 is a rear elevational view of the latch housing with the latch boltand knob removed and a dead locking pawl added and shown in inactive position.

FIG. 13 is a partial rear elevational view of the housing showing the pawl in dead locked position.

FIG. 14 is a vertical cross sectional view taken on the line 14-14 of FIG. 12.

Referring more particularly to the disclosure in the drawings wherein is shown an illustrative embodiment of the present invention, FIG. 1 discloses a night latch assembly 10 including a housing 11 having a front face 12, side walls 13,13, a rear end wall 14 and an opposite end wall 15 having an opening 16 therein. A base 17 is dimensioned to conformably fit within the housing 11 and has a tongue 18 fitting within the lower end of the opening 16.

The housing is provided with four hollow integral studs 19 having passages 21 therethrough to receive suitable fasteners or securing means to secure the lock 10 onto the interior surface of a door (not shown). The studs 19 extend inwardly from the front face 12 to terminate adjacent the rear open side of the housing in a reduced end 22 (FIG. 14) defining a positioning shoulder 23. The base 17 is provided with an opening 24 adjacent each corner to receive the reduced end 22 with the base resting on the shoulders 23. The ends 22 are staked at 25 to retain the base 17 within the housing and close the open side thereof.

The base 17 is also provided with a centrally located opening 26, an adjacent elongated slot 27 and a second opening 28 having a depending flange 29 at one edge thereof; the openings 26 and 28 being in horizontal alignment as seen in FIGS. 5 and 6. The opening 26 receives the inner reduced end 36 (FIG. 10) of a rotatable knob 31 having a manual gripping portion 32 (FIG. 1) extending through an opening 33 (see FIG. 12) in the front face 12 of the housing, an enlarged flange 34 and a rearwardly extending generally cylindrical body 35 terminating in the reduced end 36. The flange 34 of the knob 31 is provided with a pair of rearward projections or embossments 37 and 38 spaced apart by an arc of approximately The body 35 and reduced end 36 has a central opening 39 therein provided with oppositely disposed inwardly extending shoulders 41,41 to accommodate the conventional tail piece of a key-actuated tumbler lock (not shown) mounted in the exterior surface of a door with the tail piece extending through the door into the reduced end 36 of the knob.

Mounted for reciprocable movement in the housing is a latch bolt 42 having a forward latching end 43 normally projecting through the opening 16 into a suitable strike 44 (see FIGS. 2, 3 and 4). The latching end 43 is provided with a camming surface 45 to cam the bolt into the housing 11 uponengagement with the strike as the door is moved to its closed position. The'bolt has an elongated body 46 with a central elongated slot 47 therethrough and terminates in an enlarged rear end 48 having a pair of camming surfaces on one face 49 separated by the slot 47. The slot 47 receives and the latch bolt 42 emcompasses the cylindrical body portion 35 of the rotatable knob 31. One camming surface 50 is a flat surface substantially perpendicular to the longitudinal axis of the latch bolt, while the opposite camming surface 51 includes a short angular portion 52 at an angle of approximately 75 to the longitudinal axis of the bolt 42 and a second longer angular portion 53 intersecting the portion 52 and at an angle of approximately 45 to the bolt axis; the portion 53 terminating at 54 adjacent the curved rear edge 55 of the latch body.

On the opposite face 56 of the bolt body 46 is formed a projection 57 generally opposite the camming surface 50 and adapted to project into the elongated slot 27 in the base 17. Upon reciprocation of the bolt 42, the projection 57 moves in the slot 27 to guide the bolt movement and prevent canting or jamming thereof. The face 56 is also provided with a recess 58 formed adjacent the latching end 43, and having an end wall 59 in the end 43, to receive a compression spring 60. The spring 60, as seen in FIGS. 2, 3 and 4 is received in the recess 58 with one end abutting the end wall 59 and the opposite end abutting the depending flange 29 to resiliently bias the bolt to its latched position of FIG. 2.

In operation with the rim cylinder lock and tailpiece omitted, the bolt 42 and the knob 31 are shown assembled in the housing 22 in FIGS. 2, 3 and 4, with the reduced end 36 of the knob body 35 projecting into the opening 26 in the base 17. The assembly is shown in its normal latched position in FIG. 2 with the projection 37 on the knob engaging the camming surface 50 and the projection 38 engaging the portion 52 of the camming surface 51. Upon rotation of the knob 31 in a counterclockwise direction, as seen in FIG. 2, the projection 37 engages and causes the camming surface 50 to move rearwardly to retract the bolt 42, as shown in FIG. 3. Release of the knob 31 at any point in its arc of rotation allows the force of the spring 60 to return the bolt 42 and the knob 31 to the position of FIG. 2.

Rotation of the knob 31 in the clockwise direction, as seen in FIG. 2, causes the projection 38 to engage the angular camming portion 52 to retract the bolt 42; the projection 38 engaging the portion 52 for substantially the entire rearward movement of the latch bolt 42. As long as the projection 38 contacts the camming portion 52, release of the knob 31 allows the spring 60 to urge the bolt to its projected position and return the knob 31 to the position of FIG. 2. However, if the projection 38 moves beyond the camming portion 52 onto the angular portion 53 at the end of retractive movement, the projection 38 moves to the end 54 of the portion 53, with a slight forward movement of the bolt, and abuts a projection 61 in the housing to limit movement thereof. The bolt 42 is then retained in retracted position within the housing even though the knob 31 is released (FIG. 4). To return the latch bolt 42 to its projected position of FIG. 2, the knob 31 must be manually turned in a counterclockwise direction until the projection 38 moves from the angular portion 53 onto the camming portion 52, at which time the knob can be released and the spring 60 will then urge the bolt and knob to the position of FIG. 2.

FIGS. 12, 13 and 14 disclose an additional feature of the lock structure providing adead bolt arrangement. This feature includes a pawl knob 62 having a depending stem 63 extending through an opening 64 in the front face 12 of the housing 11. Within the housing, a rotatable pawl 65 is secured onto the inner end of the stem 63 so that rotation of the knob 62 rotates the pawl 65. A pair of stops 66,66 are formed on the interior surface of the front wall 12 to limit rotation of the pawl to an arc of approximately 180 Also, three detent depressions 67,67,68 are formed in the interior surface of the wall 12 with the depressions 67,67 formed adjacent the stops 66,66 and the depression 68 is located on an arc of approximately 90 from each depression 67,67 and adjacent the end wall 15. The pawl has a rounded detent 69 formed on the surface facing the wall 12 to cooperate with any one of the three depressions 67,67 or 68.

An arrowhead 71 (FIG. 1) is formed on the exposed face of the knob 62 with the point thereof aligned with the position of the pawl 65. With the latch bolt 42 in its projected position (FIG. 2), the pawl 65 is positioned between the bolt body 46 and the wall 12 and is free to rotate to any one of the three positions indicated by the detent depressions 67,67 and 68. If the pawl detent engages either of the two depressions 67,67, the pawl 65 in this position being shown in solid lines in FIG. 12 and in dotted outline in FIG. 13, the bolt 42 is free to reciprocate and/or be retained in retracted position (see FIG. 4) without interference from the pawl.

However, if the pawl 65 is positioned with the detent 69 engaging the depression 68, the pawl 65 in this position being shown in solid lines in FIG. 13, the outer end of the pawl 65 is in close proximity with the shoulder 72 formed on the inner edge of the latch bolt head 43 and prevents retraction of the bolt. Thus, positioning of the pawl with the detent 69 engaging the depression 68 provides an effective dead bolt arrangement to prevent unauthorized retraction of the bolt 42 and entry through the door. The knob 31 cannot retract the bolt I 42 until the pawl 65 is rotated by the pawl knob 62 to engage the detent 69 with either depression 67,67.

Obviously, the rotation of a suitable tail piece by a rim cylinder lock positioned in the exterior surface of the door will cause rotation of the knob 31 due to the tail piece engaging two opposite sides of the shoulders 41,41 in the central opening 39 of the knob body 35 as is conventional in door lock assemblies. The cylinder lock will actuate the bolt 42 in the same manner through the rotation of the knob 31', retraction of the bolt to the retained position (FIG. 4) requiring positive rotation of the tail piece to rotate the knob and release the bolt. The shoulders 41,41 provide a lost motion connection between the knob and the tail piece so the key can be returned to its inactive position allowing withdrawal thereof from the lock.

However, the insertion of the tail piece into the opening 39 alters permissible actuation of the knob 31 by manual actuation at the interior of the door. The position of the tail piece in the opening 39 and acting on the shoulders prevents manual rotation of the knob 31 to retract the bolt in a counterclockwise direction as seen in FIG. 3. The tail piece acting on the shoulders will not interfere with manual clockwise rotation of the knob to retract and retain the bolt in retracted position (FIG.

4) or the reverse rotation to project the bolt to latched position.

I claim:

1. A spring bolt latch assembly to be secured onto a door and cooperate with a suitable strike in a door frame therefor, comprising a housing to be secured onto the door opposite the strike, a reciprocable latch bolt in the housing movable between retracted and projected positions, means biasing the latch bolt to its projected position, a rotatable knob mounted in the housing to rotate in either clockwise or counterclockwise direction, said knob having a knob body with an enlarged flange within the housing, said bolt having an elongated central slot encompassing the knob .body in the housing, and cooperating camming means on the knob and the latch bolt to retract'the latch bolt upon rotation of said knob in either direction, said camming means including a pair of spaced camming pins on the enlarged flange, and a pair of oppositely disposed camming surfaces on the bolt, said camming surfaces on the bolt including a flat camming surface on one side of the slot engaged by one of the camming pins and an angularly disposed camming surface on the opposite side of the slot engaged by the other camming pin, said angularly disposed camming surface including a short outer angular portion disposed at an angle relative to the axis of movement of the latch bolt and a second angular portion intersecting the short angular portion and at a lesser angle relative to the axis of movement of the latch bolt than the short angular portion, said biasing means acting to project the latch bolt upon release of said knob, said camming means on said knob and latch bolt cooperating to retain the latch bolt in fully retracted position upon rotation of said knob in one direction. I

2. A spring bolt latch assembly as set forth in claim 1, including a base secured to the housing and forming one side thereof, said latch bolt having a recess adjacent the forward projecting end thereof, a flange depending from the base and aligned with the recess, and said biasing means including a compression spring having one end received in the recess and the opposite end abutting the flange.

3. A spring bolt latch assembly as set forth in claim 1, in which the short angular portion is at an angle of approximately and the second angular portion is at an angle of approximately 45 relative to the axis of movement of the latch bolt.

4. A spring bolt latch assembly as set forth in claim 1, in which the camming pin acting on the short angular portion retracts the latch bolt upon rotation of the knob and release of the knob allows the spring to return the bolt to projected position, and movement of the camming pin from the short angular portion onto the second angular portion when the bolt is fully retracted acts to retain the bolt in retracted position until forcible movement of the knob in the opposite direction initiates projection of the bolt.

5. A spring bolt latch assembly as set forth in claim 1, in which said bolt has a curved inner end wall defining the inner end of the slot and cooperating with the knob body to limit projection of the bolt.

6. A spring bolt latch assembly as set forth in claim 2, in which said base has an elongated slot parallel to the axis of movement of the bolt, and a projection on the bolt received in the elongated slot to guide the movement of the bolt.

7. A spring bolt latch assembly as set forth in claim 1, including dead locking means in the housing cooperating with the bolt to retain the bolt in projected position and prevent rotation of the knob.

8. A spring bolt latch assembly as set forth in claim 7, in which said dead locking means includes a pawl swingably mounted in said housing between inactive positions and a dead locking position, and a shoulder on said bolt engaging the free end of the pawl in its dead locking position.

9. A spring bolt latch assembly as, set forth in claim 8, including a pawl knob on the exterior of the housing and operatively connected to the pawl to initiate swinging movement thereof, and.detent means on the pawl and in the housing to yieldably retain the pawl in an inactive or the dead locking position.

10. A spring bolt latch assembly as set forth in claim 9, in which said pawl swings through an arc of 180 between its two inactive positions, and the dead locking position is removed from and centrally located between the inactive positions. 

1. A spring bolt latch assembly to be secured onto a door and cooperate with a suitable strike in a door frame therefor, comprising a housing to be secured onto the door opposite the strike, a reciprocable latch bolt in the housing movable between retracted and projected positions, means biasing the latch bolt to its projected position, a rotatable knob mounted in the housing to rotate in either clockwise or counterclockwise direction, said knob having a knob body with an enlarged flange within the housing, said bolT having an elongated central slot encompassing the knob body in the housing, and cooperating camming means on the knob and the latch bolt to retract the latch bolt upon rotation of said knob in either direction, said camming means including a pair of spaced camming pins on the enlarged flange, and a pair of oppositely disposed camming surfaces on the bolt, said camming surfaces on the bolt including a flat camming surface on one side of the slot engaged by one of the camming pins and an angularly disposed camming surface on the opposite side of the slot engaged by the other camming pin, said angularly disposed camming surface including a short outer angular portion disposed at an angle relative to the axis of movement of the latch bolt and a second angular portion intersecting the short angular portion and at a lesser angle relative to the axis of movement of the latch bolt than the short angular portion, said biasing means acting to project the latch bolt upon release of said knob, said camming means on said knob and latch bolt cooperating to retain the latch bolt in fully retracted position upon rotation of said knob in one direction.
 2. A spring bolt latch assembly as set forth in claim 1, including a base secured to the housing and forming one side thereof, said latch bolt having a recess adjacent the forward projecting end thereof, a flange depending from the base and aligned with the recess, and said biasing means including a compression spring having one end received in the recess and the opposite end abutting the flange.
 3. A spring bolt latch assembly as set forth in claim 1, in which the short angular portion is at an angle of approximately 75* and the second angular portion is at an angle of approximately 45* relative to the axis of movement of the latch bolt.
 4. A spring bolt latch assembly as set forth in claim 1, in which the camming pin acting on the short angular portion retracts the latch bolt upon rotation of the knob and release of the knob allows the spring to return the bolt to projected position, and movement of the camming pin from the short angular portion onto the second angular portion when the bolt is fully retracted acts to retain the bolt in retracted position until forcible movement of the knob in the opposite direction initiates projection of the bolt.
 5. A spring bolt latch assembly as set forth in claim 1, in which said bolt has a curved inner end wall defining the inner end of the slot and cooperating with the knob body to limit projection of the bolt.
 6. A spring bolt latch assembly as set forth in claim 2, in which said base has an elongated slot parallel to the axis of movement of the bolt, and a projection on the bolt received in the elongated slot to guide the movement of the bolt.
 7. A spring bolt latch assembly as set forth in claim 1, including dead locking means in the housing cooperating with the bolt to retain the bolt in projected position and prevent rotation of the knob.
 8. A spring bolt latch assembly as set forth in claim 7, in which said dead locking means includes a pawl swingably mounted in said housing between inactive positions and a dead locking position, and a shoulder on said bolt engaging the free end of the pawl in its dead locking position.
 9. A spring bolt latch assembly as set forth in claim 8, including a pawl knob on the exterior of the housing and operatively connected to the pawl to initiate swinging movement thereof, and detent means on the pawl and in the housing to yieldably retain the pawl in an inactive or the dead locking position.
 10. A spring bolt latch assembly as set forth in claim 9, in which said pawl swings through an arc of 180* between its two inactive positions, and the dead locking position is 90* removed from and centrally located between the inactive positions. 